America’s only heavy icebreaker- the Coast Guard’s Polar Star- is making its way north through the icy waters of the arctic- yet as they progress along their journey, crew members report hearing strange noises keeping them up at night.
According to a press release from the Coast Guard, as the Polar Star pushed northwards through a heavy blanket of sea ice, crewmembers began to discuss a “persistently clamorous sound.”
Ice striking the hull of a ship is often loud, but the shrieking produced by the northern sea ice is of an entirely different breed. Sailors have described the sound as “a perpetual car-crash, a blaring elephant, freight train, or driving through concrete.”
It wasn’t immediately clear what made the northern ice so much louder than its polar counterpart, but a scientist aboard the Polar Star thinks he knows the answer. Evan Neuwirth, an ice analyst from the US National Ice Center, believes that the temperature of the ice may be the contributing factor.
Winter sea ice is colder than the summer ice that the Polar Star usually encounters on its typical deployments to the South Pole. That makes it more dense and more brittle than other ice. Thus, the energy the Polar Star uses to break the ice is greater, producing an ear-piercing noise. In Neuwirth’s words, the difference is like throwing a snowball at the ship’s hull compared to a chunk of ice.
As the Polar Star continues its voyage, the crew will continue to experience the remote serenity of the arctic- but none of its silence.